Amazingly enough, most of these problems can be fixed rather quickly if we, as a species, decide it is important enough for us to allocate more money to fighting pollution and over fishing. Sadly, it is not likely to happen because even sailors from developed countries trivialize this very real problem.

FWIW the number and variety of birds and animals have increased in the area I grew up and the water is cleaner. It is possible to turn this stuff around.

On the other hand I had the misfortune of finding myself swimming through a "garbage patch" on a local lake a few years ago while training for a triathlon. This was after a storm. Obviously this isn't just a third world problem. The city has started to divert storm sewers so that they don't run straight into the lakes and rivers and instead goes into holding ponds.

For several years on Earth Day my family along with hundreds of other volunteers would pick up the garbage around nearby lakes and beaches. You feel good about helping to clean things up but at the same time distressed at how much junk ends up back there in just one years time. When I first moved here I couldn't figure out why the concession stands at the beaches wouldn't give out straws (the restaurants that have taken over do now I think). After picking up what seemed like thousands of them, I know why.